package com.louis.iread.utils;

import android.graphics.Bitmap;
import android.graphics.Matrix;

/**
 * Created by louis on 17-3-29.
 */

public class BitmapUtil {
    /**
     * 缩放图片
     *
     * @param bm
     * @param newWidth
     * @param newHeight
     * @return
     */
    public static Bitmap getBitmap(Bitmap bm, int newWidth, int newHeight) {
        // 获得图片的宽高
        int width = bm.getWidth();
        int height = bm.getHeight();
        // 计算缩放比例
        float scaleWidth = (float) newWidth / width;
        float scaleHeight = (float) newHeight / height;
        // 取得想要缩放的matrix参数
        Matrix matrix = new Matrix();
        matrix.postScale(scaleWidth, scaleHeight);
        // 得到新的图片
        return Bitmap.createBitmap(bm, 0, 0, width, height, matrix, true);
    }
}
